Lightened Yaris

[Idahotom]

I've had my '08 for a week now, and here is what I have done so far: removed everything behind the front seats, including the jack under the drivers seat and the spare and even the bracket/mount for the spare (I had to drill out the spot welds). Today I pulled off the wheel covers! I really don't care what it looks like, obviously.

I build and fly aircraft, so weight reduction is a natural for me, and of course I had a good scale to document things. I also live up a mountainside, 1000' above the valley below, and for years have drove without a spare in any of my rigs. I can't really say if I've noticed a difference as I am so new to it anyway, but it stands to reason in a car so light already. removing 100+lbs of stuff will pay off, reducing empty weight always does I don't care what it is. Some particulars:

wheels covers: 3.6 (3 lbs. 6ozs.)
owners manual !! 2.0
flip up deck 2.13
deck carpet 2.10
tool trays with tools 6.8
main deck 11.2
spare 21.14
jack 3.1
rear seat bottom 10.9
seat frame 6.9
seat back 37.5 !!!!!!!!!!
spare support bracket 1.6
rear pass. carpet 1.15
total 111 lbs and 13 ozs.

All of this is neatly stored away, and will be re-installed when selling. I have looked at the various options, and have decided to do nothing that adds weight (like a rear sway bar, though they sound neat). I have taken an old blanket and spread it over the exposed metal where the spare and the seat used to be, and that is all I plan to do. My next trip past a certified scale I will weigh it, subtract for me and the dog, and then look to see what else I can safely remove, if anything.

My first trip down the mountain and to my workplace 14 miles away (luckily on a road posted 45, most drive it at 50+) : 62 MPG, coming back the same way (pulling hill) 40.2. I've had a Scan Gauge for some time, and it is well calibrated. Assuming a empty weight to start of 2300 lbs, that represents a weight loss of about 5%. Also, it didn't cost a dime!

Yesterday in town I did get on it for the first time, while pulling into traffic, and was surprised! It hauls ass pretty good, it made me laugh! Great fun car.

I also found the passenger seat weighs 47 lbs., for those wanting to go know.

[Klink10]

Thanks for adding the weights to items removed. Kinda curious as to the owners manual weighing 2 lbs. Seat belts (rear)? Had removed my spare at one time until I thought of flat away from home. Keep us posted.

[fnkngrv]

I removed my spare a long time ago from my sedan, but never weighed it...I guess that balances out my Bazooka tube then since that has got to be around the same weight....good info. As for the owner's manual...doesn't surprise me in the least. Paper weighs a lot....sounds silly, but true.

[why?]

Show us some pictures! Especially I'd love to know what you did to take of that idiotic spare tire mount, I would love to get rid of that thing. And what it looks like with it off.

Great job on removing the weight.

[Idahotom]

Thanks for adding the weights to items removed. Kinda curious as to the owners manual weighing 2 lbs. Seat belts (rear)? Had removed my spare at one time until I thought of flat away from home. Keep us posted.

It was probably something the dealer added, but it was a large vinyl case with all the warranty info etc. and will really do me more good at home in the file cabinet then in the glove box.

The spare bracket was spot welded into place in six places, I drilled out the welds and until I get some 3/16" pop rivets (the largest my gun will pull) I just shot some caulk in the holes, as I live down a 1 mile dusty dirt road. IF I ever put it back, I'll use stainless 3/16" rivets and it'll be almost as good as new. It bugged me the way it stuck up in the way, after the spare was removed, so it had to go!

[nemelek]

I should go a diet. That would be another 20 pounds.

[roadrunner]

Thanks for the info with weights.

[Palmer812]

I removed my spare tire bracket when I did my subwoofer enclosure. I covered the holes with Hushmat noise deadening. Here is a pic if anyone is curious.
37741

[why?]

So six pretty obvious welds. Cool beans. Thank you for the pic. Did you drill the welds out too? And how would you explain exactly what that means to someone completely clueless. Heh, I'll talk to some body shop peoples, I bet me doing that myself would be disastrous.

[Palmer812]

Literally drill them out. I think I used a 1/4" drill bit in a cordless drill. You put the drill bit in the center of the weld and drill it until you go through the weld and the floor of the car. Pretty simple.

[Idahotom]

Literally drill them out. I think I used a 1/4" drill bit in a cordless drill. You put the drill bit in the center of the weld and drill it until you go through the weld and the floor of the car. Pretty simple.

Yes, pretty simple. Just start with a smaller bit and work up until the weld is drilled out. FIRST though stick your head underneath and eyeball what is there and the consequences if you shove that last and longest drill bit too far through the hole. There is plenty of room, but there is "stuff" (some kind of fuel related thing, looks like maybe a fuel vapor recovery box or something, whatever it was I didn't want to mess with it) underneath, just be aware of it before drilling, and you could always use a drill stop, a short piece of metal tubing or whatever so once you drill through the bit can't go any further, simple.

[HTM Yaris]

Weight loss is always good , but try to keep in mind center of gravity . Also by removing the the back seat your car is now more flexible and top heavy . I'm not complaining but just pointing out some safety concerns .

If ya want more weight saving ideas try these .
1. Switch to Braille battery - 20 lbs
2. Remove windshield fluid reservoir -10 lbs
3. Buy wheels that weight less than 11 lbs -15-20 lbs
4. Fill gas tank to halfway mark ( about 5.5 gallons ) -50 lbs
5. Remove front seat -40 lbs ( actually I think it weighs more :iono: )
6. Remove passenger side airbags - 10-20 lbs

Another downside to weight removal is that the Yaris has such a large cross section that wind or passing vehicles will greatly affect directional stability .

[Kal-El]

Weight loss is always good , but try to keep in mind center of gravity . Also by removing the the back seat your car is now more flexible and top heavy . I'm not complaining but just pointing out some safety concerns .

If ya want more weight saving ideas try these .
1. Switch to Braille battery - 20 lbs
2. Remove windshield fluid reservoir -10 lbs
3. Buy wheels that weight less than 11 lbs -15-20 lbs
4. Fill gas tank to halfway mark ( about 5.5 gallons ) -50 lbs
5. Remove front seat -40 lbs ( actually I think it weighs more :iono: )
6. Remove passenger side airbags - 10-20 lbs

Another downside to weight removal is that the Yaris has such a large cross section that wind or passing vehicles will greatly affect directional stability .

Now that's going too far. Side airbags could be the difference between life and death. Not worth saving $2 a year.

Losing the heavy gas seems like the biggest bang for the least sacrifice. People forget how heavy all those gallons of gas weigh.

[TLyttle]

Lotsa fun... I did the same to an old Austin 1100 many years ago. Scale weight was 1550 lbs, and I took out EVERYTHING. I was left with an driveline, 2 seats, and not much else. Door handles and window winders were replaced with sheet metal screws to hold the doors closed and the windows up, anything and everything came out. Weight savings (I weighed it all as it came out) 470lbs. Driveline remained stock, but the performance was sparkling to say the least, fuel economy was amazing.

It was just an experiment, but its lessons were very clear!

[why?]

Weight loss is always good , but try to keep in mind center of gravity . Also by removing the the back seat your car is now more flexible and top heavy . I'm not complaining but just pointing out some safety concerns .

If ya want more weight saving ideas try these .
1. Switch to Braille battery - 20 lbs
2. Remove windshield fluid reservoir -10 lbs
3. Buy wheels that weight less than 11 lbs -15-20 lbs
4. Fill gas tank to halfway mark ( about 5.5 gallons ) -50 lbs
5. Remove front seat -40 lbs ( actually I think it weighs more :iono: )
6. Remove passenger side airbags - 10-20 lbs

Another downside to weight removal is that the Yaris has such a large cross section that wind or passing vehicles will greatly affect directional stability .

The car weighs enough that you do not have to worry about center of gravity unless you figure out how to drop 1000lbs. A few hundred pounds will only allow the center of gravity creep closer to the driver, which is where you want it.

And removing the passenger side air bag is probably illegal in most states at this point.

Oh and if you are interested in Braille batteries, check out Deka. They make braille batteries, and you can get an off name battery that is identical for 1/3 of the price.

[HTM Yaris]

Let me clarify . The center of gravity I was referring to is in the transverse plane ( up, down ) . All of the mentioned weight removal is below the window line , thus making a top heavy car . A top heavy car with a large cross section on a windy , icy day will not be safe . When considering weight reduction all three planes( coronal , sagital , and transverse) must be taken into consideration .

Also I meant to remove pass. seat . So if you have no pass. seat ...no pass. airbags are needed . I don't know about legality , but I do now that I've never heard of anyone asking to see the airbags when being pulled over .

Thanks for the battery tip :headbang:

[docB]

What has all of this weight loss done for the ride quality? Everything you mention, save the light wheels is sprung weight. Rotating parts are really good things to put on a diet. I light weight flywheel would cut the pounds and pep up throttle response. Don't forget to loose the plastic engine cover. I did not weigh it, but I like taking wt off of those front wheels.
doc

[why?]

Let me clarify . The center of gravity I was referring to is in the transverse plane ( up, down ) . All of the mentioned weight removal is below the window line , thus making a top heavy car . A top heavy car with a large cross section on a windy , icy day will not be safe . When considering weight reduction all three planes( coronal , sagital , and transverse) must be taken into consideration .

Also I meant to remove pass. seat . So if you have no pass. seat ...no pass. airbags are needed . I don't know about legality , but I do now that I've never heard of anyone asking to see the airbags when being pulled over .

Thanks for the battery tip :headbang:

i understand, but losing 111lbs does not make the car top heavy. The driver alone probably weighs that much, never mind the engine weighs that much, and the roof simply does not. At some point, yes, you would have to worry about the car being top heavy, but it would have to be a very significant weight loss because the roof simply does not weigh that much.

As for the airbags, in mass if the airbag light is on, the car will not pass inspection. Since the car comes with a passenger airbag, in my state it must be installed or you cannot drive the car on the street.

I'd be shocked if it wasn't the same way in most NE states, and the other states that seem to follow cali in lockstep. It is just worthwhile to check out the laws before doing anything like that to make 100% sure you can do it and still drive the car legally.
What has all of this weight loss done for the ride quality? Everything you mention, save the light wheels is sprung weight. Rotating parts are really good things to put on a diet. I light weight flywheel would cut the pounds and pep up throttle response. Don't forget to loose the plastic engine cover. I did not weigh it, but I like taking wt off of those front wheels.
doc

I don't think it has hurt ride quality, and it definitely makes the car more fun to drive.

[HTM Yaris]

I say the roof weighs close to 300 lbs ( actual roof , glass, hatch, and panels etc) , but I doubt anyone will cut off their roof so we could find the exact weight :smile:

Also by definition any time you remove weight from the center of any object it makes it top heavy . You are correct in thinking the Yaris won't tip over at every turn by losing 111 lbs , but I am correct in saying it won't be a fun drive in a lightened Yaris on a 12 % grade in icy/windy conditions . Not to mention big rigs blowing past you and pushing you around .

To answer the ride quality question , the heavier Yaris will give the better ride quality . Go try it out for yourself . Just ride in you Yaris by yourself . Then ride with 1 or 2 adult passengers in the back seat . You will feel the difference fo sho .

Here in South Carolina , we don't have car inspections . But if we did and I wanted to remove the pass. airbag , I would be smart enough to remove the indicator bulb as well :wink:

Oh about the flywheel , true you can lose a lot of rotating mass , but the trade off is drivability . IMO the stock Yaris flywheel is perfect . With a light weight flywheel you will have to "blip" the throttle to match revs to make gear transitions smooth . With the stock flywheel the weight of it keeps the momentum up making gear changes much smoother .

[why?]

I say the roof weighs close to 300 lbs ( actual roof , glass, hatch, and panels etc) , but I doubt anyone will cut off their roof so we could find the exact weight :smile:

Also by definition any time you remove weight from the center of any object it makes it top heavy . You are correct in thinking the Yaris won't tip over at every turn by losing 111 lbs , but I am correct in saying it won't be a fun drive in a lightened Yaris on a 12 % grade in icy/windy conditions . Not to mention big rigs blowing past you and pushing you around .

To answer the ride quality question , the heavier Yaris will give the better ride quality . Go try it out for yourself . Just ride in you Yaris by yourself . Then ride with 1 or 2 adult passengers in the back seat . You will feel the difference fo sho .

Here in South Carolina , we don't have car inspections . But if we did and I wanted to remove the pass. airbag , I would be smart enough to remove the indicator bulb as well :wink:

Oh about the flywheel , true you can lose a lot of rotating mass , but the trade off is drivability . IMO the stock Yaris flywheel is perfect . With a light weight flywheel you will have to "blip" the throttle to match revs to make gear transitions smooth . With the stock flywheel the weight of it keeps the momentum up making gear changes much smoother .

I can't say anything to 12% grades or seriously windy conditions, as I don't think I've ever driven on a grade that steep for anything longer than an 1/8 mile or less probably, I have never had a problem with wind at all with the Yaris. And I've never had a problem driving by big rigs, something i did a ton of when I drove from orlando to mass.

You are technically right about ride quality. That depends what type of ride quality you are looking for. If you are looking for super cushy, then don't touch anything. I have had 3 people or more in my car 2 times in the 4+ years I have owned it. I enjoy the ride better with all the crap out of it, where I here all the road noise and stuff hitting off the bottom of the car. I find that cool.

You're funny. In Mass, they attach the car's computer directly to an inspection computer, so they'd see the code.

The thing about rotating mass is spot on. Lightened pulley's and a lighter flywheel make the car harder to drive, and make the idle kinda nutty. For me the trade off is worth it, for others, maybe not.

[Idahotom]

CG?? Not enough to matter, besides I'd bet the CG is pretty much AT the seat level, what with the heavy engine and running gear. I had a high cross wind the other day, and yes I did get pushed around some, but do not know how it compared to a fully loaded HB as I am new to the genre.

The thing I really like is how well it coasts: I have a few places on a road I drive a lot, where I can put it in neutral, and maintain the speed limit for a mile, only slowing as I near a stop sign, as the slope pretty near matches the drag. I've done this for years in all my rigs on the same road, but the Yaris, probably mostly because it appears to be a pretty low drag rig, goes the furtherst.

Just today I went down the mountain (1,000' drop), into town 12 miles at 49 mph (on a state road posted at 45 that everyone drives 50+) and all around town running errands, then the same in reverse (not the gear, but order). 39 miles according to the calibrated Scan Gauge, and 51.8 MPG. No radical techniques were used just mild/unnoticable to others basic hypermiling. Windows down with the extra drag of the dog hanging his head out.

[HTM Yaris]

yeah I love to drive by myself without the radio on just to hear all the car sounds .

I have notices that the Yaris utilizes the slipstream(drafting) very well . I mean staying a few car lenghts back not right on the bumper . I'm always finding myself "easin" up on the gas when someone is in front of me , b/c Yaris sneaks up on the vehicle ahead of me .

[HTM Yaris]

True CG is right about seat level on the transverse plane ( up , down ), but on the coronal plane ( front, back ) you have basically added 90lbs to the front . The effect of the weight reduction won't come into play until you get to a panic situation . If you ever have to make a quick lane change or a quick lane change with heavy braking you will encounter severe understeer . Also if you change gears on a turn you will encounter oversteer . I mean that the over/under steer will be more pronounced than usual .

Idahotom , check out this vid of me on track . In this vid I have done the exact same weight reduction you described . Pay special attention to 1:03 to 1:08 . That oversteer came from me just releasing the gas while turning . If I had been on stock tires the car would have probably oversteered past the point that I could recover .

http://www.youtube.com/watch?v=UCdCdT972Uk

Try a track day or autox to learn about your car's abilities . You will definately have fun while learning about your handling . Not to mention you will meet some pretty cool people .
Oh if you do decide to do Track/Autox ... your dog will need a helmet :biggrin:

[Idahotom]

I see what you mean, but as the coronal datum point is somewhat unknown (?) the net effect is probably less then 90 lbs., it all depends on the length of the lever arm of course. In other words, if the CDP is close to the rear seat, removing the seat would have less effect then if it (the CDP) was several feet further forward.

Having said that mouthfull, I agree that the loading is altered, and the handling. No tracks around here, but winter snow and twisty mountains roads substitute pretty well. At the outer limits of control, either track driving or a panic situation, it could well make a difference. So... did you put your seat and the other stuff back in due to your track driving insights, or is it just something to keep in mind when pushing it to the limit? I sure like the lightness as is.

The GREAT thing about hypermiling, drafting big rigs and blowing through stop signs aside, it is pretty safe, I NEVER speed anymore, I'm always in Grandma mode these days as it is all about keeping the ScanGauge happy, and I was quite amused when I saw all the aftermarket handling mods not to mention the supercharged/turboed Yaris's, who'd ever thought! All I know for sure is I got 61 MPG coming down the mountain into town, 51.8 back up, and never got over 50 mph. Good vid!

True CG is right about seat level on the transverse plane ( up , down ), but on the coronal plane ( front, back ) you have basically added 90lbs to the front . The effect of the weight reduction won't come into play until you get to a panic situation . If you ever have to make a quick lane change or a quick lane change with heavy braking you will encounter severe understeer . Also if you change gears on a turn you will encounter oversteer . I mean that the over/under steer will be more pronounced than usual .

Idahotom , check out this vid of me on track . In this vid I have done the exact same weight reduction you described . Pay special attention to 1:03 to 1:08 . That oversteer came from me just releasing the gas while turning . If I had been on stock tires the car would have probably oversteered past the point that I could recover .

http://www.youtube.com/watch?v=UCdCdT972Uk

Try a track day or autox to learn about your car's abilities . You will definately have fun while learning about your handling . Not to mention you will meet some pretty cool people .
Oh if you do decide to do Track/Autox ... your dog will need a helmet :biggrin:

[why?]

For me, oversteer is the desired result. Oversteer in fwd cars is just awesome.

[TLyttle]

Oversteer can have its advantages, but neutral is where one wants to be. Neutral at all speeds is the fastest way from point A to point B. I concur that a tail-happy car is really fun, but too much of a good thing becomes lethal, ie, early Porsches...

[why?]

Oversteer can have its advantages, but neutral is where one wants to be. Neutral at all speeds is the fastest way from point A to point B. I concur that a tail-happy car is really fun, but too much of a good thing becomes lethal, ie, early Porsches...

Not really interested in the fastest way from point a to point b. Interested in enjoying the drive. If I was interested in speed I would buy a sports car.

[Jason@SportsCar]

Our car is down to 1860lbs... The only thing trying to make it tip over the is sticky Goodyear racing slicks. Lighter is better.

[MUSKOKA800]

A bit extreme. Why not just drive a kart if you don't want creature comforts.
Hmmm... remove the steering wheel and clamp a pair of vicegrips onto the shaft. Save more weight and have a tool handy when in need.

[why?]

A bit extreme. Why not just drive a kart if you don't want creature comforts.
Hmmm... remove the steering wheel and clamp a pair of vicegrips onto the shaft. Save more weight and have a tool handy when in need.

why drive at all? Why not walk? If you want creature comforts why buy a yaris? Go get a lexus or some other car that actually has them.

Stop being a judgmental moron and realize that everyone else does not want the exact same thing you do.

[Biff]

why drive at all? Why not walk? If you want creature comforts why buy a yaris? Go get a lexus or some other car that actually has them.

Stop being a judgmental moron and realize that everyone else does not want the exact same thing you do.

right...:headbang:

[KrazyDawg]

What about replacing the hood, trunk, and side mirrors with carbon fiber? It might not be cost effective to go this route.

[why?]

What about replacing the hood, trunk, and side mirrors with carbon fiber? It might not be cost effective to go this route.

it is definitely on my list of things to do, but as you mentioned, it is not cheap.

eventually, i will get the MI hood, (http://shop.microimageonline.com/Micro-Image-vented-hood-YARIS-liftback-MI-hd1.htm) and probably a seibon carbon hatch, unless there is better manufacturers that i don't know about yet.

i can't see the side mirror covers being worth it. I doubt they could possibly save any amount of weight compared to the cost. I'd almost thing titanium exhausts would be a better idea than mirror covers.

[Jason@SportsCar]

A bit extreme. Why not just drive a kart if you don't want creature comforts.
Hmmm... remove the steering wheel and clamp a pair of vicegrips onto the shaft. Save more weight and have a tool handy when in need.

I think you missed my point... Making the car lighter does not make it more tipsy. Make it lighter and you will have less inertia trying to pull it over. Added bonus, better acceleration, brakes quicker, handling improves as well as using less fuel.

[docB]

Light is might. A lighter car, all other factors equal, will be quicker, better economy, etc...If one can lighten the vehicle in such a manner that the ratio of weight held up by the springs to the unsprung weight stays constant, then the vehicle will still ride "nice". Just gutting the interior can be good. At the Auto-x my Yaris ran in, I found a point where taken out the weight made the car tougher to drive. Over steer got to be an issue. I think you get a great benefit from lighter parts that spin or reciprocate. Lighter wheels and or tires, fly wheel & clutch, connecting rods. But how deep are your pockets?
doc

[Idahotom]

"LIGHT IS MIGHT", I like it!

My own take on adding lightness (?), at least on my Yaris, is also not to spend any money, as much as I'd like to carbon fiber everything, lighter wheels etc. Along with that, I'd rather not do anything that'd effect the resale value. While I admire the people who have the deep pockets to REALLY lighten things up, my focus is on not spending any money and making it lighter.

I've noticed just pushing it around in my shop is SO easy, and I've gotten in the habit of, after raising my shop door (converted hangar door and no remote) I just push it outside, then go back in the shop and close the door, then get in and finally start it, thus saving a minute or so of idling. Nothing like a ScanGauge to show you how idling really cuts into your mileage!

After looking at the aftermarket sway bars, I decided not to get one, too heavy! It is zippy enough on the corners as is, I'll just live with it stock. It's still pretty fun to drive! It might be too much fun with front and rear sway bars........

[HTM Yaris]

Tom: for track and autox I take out the rear "junk" so that I can utilize oversteer . In the mountains I leave everything in so that I can utilize understeer . I don't want my tail to be in the opposing lane !

Jason: First of all , I really admire what you have done with the Yaris :bow:

But it is really unfair to compare your fully track prepped Yaris with a street driven Yaris . I mean your Yaris looks like it has the correct weight reduction measures ( in all 3 planes ) . I mean really , those Goodyear ( which have extra stiff sidewalls BTW )slicks are enough to keep any vehicle from tipping over :smile: Not to mention I feel you have a custom suspension among other things . Try this , put your stock Goodyears on and put your glass back in or up ( not sure if you removed/replaced your glass ) . I feel certain that the stock tires will roll onto the sidewall then the wheels will dig in to the tarmac , then loopedy loop , you will make some body shop happy :frown:

Light is might . That is correct to a point . To the point that safety is compromised .
The OP doesn't have a roll cage to stiffen the Yaris up after the reduction in weight . Nor does he have 10.5" slicks with a custom suspension . Nor does he have the driving experience(Yaris) in a panic/performance situation like Jason does .

In no way am I saying that weight reduction shouldn't be done . I'm just trying to point out the potential pitfalls . Another pitfall I forgot to mention is that the Yaris will be more likely to hydroplane with weight reduction . I can't speak for anybody else , but I would not want to be hydroplaning on the downside of a 12% grade :eyebulge: Not saying that will happen , but the potential will be increased with weight reduction .

[Jason@SportsCar]

But it is really unfair to compare your fully track prepped Yaris with a street driven Yaris . I mean your Yaris looks like it has the correct weight reduction measures ( in all 3 planes ) . I mean really , those Goodyear ( which have extra stiff sidewalls BTW )slicks are enough to keep any vehicle from tipping over :smile: Not to mention I feel you have a custom suspension among other things . Try this , put your stock Goodyears on and put your glass back in or up ( not sure if you removed/replaced your glass ) . I feel certain that the stock tires will roll onto the sidewall then the wheels will dig in to the tarmac , then loopedy loop , you will make some body shop happy :frown:

Light is might . That is correct to a point . To the point that safety is compromised .
The OP doesn't have a roll cage to stiffen the Yaris up after the reduction in weight . Nor does he have 10.5" slicks with a custom suspension . Nor does he have the driving experience(Yaris) in a panic/performance situation like Jason does .

In no way am I saying that weight reduction shouldn't be done . I'm just trying to point out the potential pitfalls . Another pitfall I forgot to mention is that the Yaris will be more likely to hydroplane with weight reduction . I can't speak for anybody else , but I would not want to be hydroplaning on the downside of a 12% grade :eyebulge: Not saying that will happen , but the potential will be increased with weight reduction .

I would guess you have not drive on a slick... The tires are trying to pull the car over, not stick it to the ground. I have had it on two wheels at least once per race this season - more than once without clipping the curbs, just by grip alone. Street tires will not generate enough traction to pull the car over unless you hit something. As far as sidewall stiffness, that is largely offset by the fact we roll out with 19psi in the slicks, they roll on to the sidewall by design. A great way to pick up MPG is extra tire pressure, a few extra psi can help.

Less weight builds traction, as the tires are not have to work as hard to hold the weight up. More weight on a tire does not make it work more efficiently. At the initial moment of inertia the extra grip will help to prevent wheel spin, but once the car has moved even a fraction of an inch the weight is hurting efficiency.

Worrying about the effect of the trivial amount of weight you could remove and keep the car civilized for the street is a waste of energy.

If you want to use a hydroplaning example keep in mind that the inertia of the heavier car will carry it longer than the lighter car, and it will take longer to recover. You want to prevent hydroplaning, use a better tire.

Manufacturers are going to alternative lightweight materials for a many reasons... It helps fuel economy for one. Another is safety. Look at the numbers, a full size van does not fair better than a lightweight compact when it comes to occupant safety.

No one should be suggesting removal of any safety equipment, or any devices that compromise the structure of the car, but there are things that can be removed without a dangerous downside.

[why?]

"LIGHT IS MIGHT", I like it!
My own take on adding lightness (?), at least on my Yaris, is also not to spend any money, as much as I'd like to carbon fiber everything, lighter wheels etc. Along with that, I'd rather not do anything that'd effect the resale value. While I admire the people who have the deep pockets to REALLY lighten things up, my focus is on not spending any money and making it lighter.

I've noticed just pushing it around in my shop is SO easy, and I've gotten in the habit of, after raising my shop door (converted hangar door and no remote) I just push it outside, then go back in the shop and close the door, then get in and finally start it, thus saving a minute or so of idling. Nothing like a ScanGauge to show you how idling really cuts into your mileage!

After looking at the aftermarket sway bars, I decided not to get one, too heavy! It is zippy enough on the corners as is, I'll just live with it stock. It's still pretty fun to drive! It might be too much fun with front and rear sway bars........

the front sway bar isn't really worth it, imo. the stock one is only 1 mm smaller i believe. Everyone says the rear is amazing, but I am still with you, too heavy for my tastes.

It would be different if i wanted to add power, but i really just want to add lightness.

Tom: for track and autox I take out the rear "junk" so that I can utilize oversteer . In the mountains I leave everything in so that I can utilize understeer . I don't want my tail to be in the opposing lane !

Jason: First of all , I really admire what you have done with the Yaris :bow:

But it is really unfair to compare your fully track prepped Yaris with a street driven Yaris . I mean your Yaris looks like it has the correct weight reduction measures ( in all 3 planes ) . I mean really , those Goodyear ( which have extra stiff sidewalls BTW )slicks are enough to keep any vehicle from tipping over :smile: Not to mention I feel you have a custom suspension among other things . Try this , put your stock Goodyears on and put your glass back in or up ( not sure if you removed/replaced your glass ) . I feel certain that the stock tires will roll onto the sidewall then the wheels will dig in to the tarmac , then loopedy loop , you will make some body shop happy :frown:

Light is might . That is correct to a point . To the point that safety is compromised .
The OP doesn't have a roll cage to stiffen the Yaris up after the reduction in weight . Nor does he have 10.5" slicks with a custom suspension . Nor does he have the driving experience(Yaris) in a panic/performance situation like Jason does .

In no way am I saying that weight reduction shouldn't be done . I'm just trying to point out the potential pitfalls . Another pitfall I forgot to mention is that the Yaris will be more likely to hydroplane with weight reduction . I can't speak for anybody else , but I would not want to be hydroplaning on the downside of a 12% grade :eyebulge: Not saying that will happen , but the potential will be increased with weight reduction .

what Jason said. You have it exactly opposite. stock and street tires make it harder for the car to tip over. a street tire would rather slide, not grip, and getting a street tire on the sidewalls in almost impossible.

You should note that the one known Yaris that tipped at an autocross had a stock suspension and some of the stickiest tires you can buy for the street.

And then re-read what Jason wrote.

[ctrj]

What are getting for fuel mileage with all of the weight reduction? Pencil and paper calcuations only, Scan Gauge numbers do not count!

[why?]

What are getting for fuel mileage with all of the weight reduction? Pencil and paper calcuations only, Scan Gauge numbers do not count!

so accuracy doesn't matter? lol.

[scape]

I think as tempting as it is to lighten the rear, I personally would prefer to do this only if I planned to tweak the suspension a bit. having an even heavier front end seems silly without tuning the car further.
I do think lightening the front needs less tuning overall, and has an even more drastic impact.
anyways, you can always add your notes to this thread: http://yarisworld.com/forums/showthread.php?t=17526

I was hoping we could get more of these calculations on the forums :)

[Idahotom]

What are getting for fuel mileage with all of the weight reduction? Pencil and paper calcuations only, Scan Gauge numbers do not count!

Keeping in mind I have only had my Yaris home for 3 weeks, but had a Scan Gauge on an earlier car ('98 Honda Civic, 38 mpg) so am somewhat experienced at the milder forms of hypermiling, I am getting 42 t0 43 mpg. Checked at the pump (the same pump everytime), the station I use is still 100% good old gasoline, no ethanol. Other then the weight reduction, all I have done is run the still stock tires at 44 PSI. I also use my cruise control almost all the time, even in town on long stretches (mile or so) of 35 to 45 mph streets, pretty flat though. I also use it on the interstate, even when hilly, I just like the convinence.

Having to pull a 1,000' grade every day to get home, for me anyway it makes sense and just feels right to not haul any dead weight up with me. I also like not having it with me when going down, it is a win/win. If all I did was level driving I wouldn't be quite so anal about it. I even made a point of getting a small dog, 20 lbs, and keep him on a strict diet. Sure, people tell me all the time "that dog looks like he's starving", but every little bit helps. Making him run uphill helps keep the weight down also.

[scape]

I even made a point of getting a small dog, 20 lbs, and keep him on a strict diet. Sure, people tell me all the time "that dog looks like he's starving", but every little bit helps. Making him run uphill helps keep the weight down also.

hahaha ;)

[KrazyDawg]

I even made a point of getting a small dog, 20 lbs, and keep him on a strict diet. Sure, people tell me all the time "that dog looks like he's starving", but every little bit helps. Making him run uphill helps keep the weight down also.
Don't forget about your own diet. ;) It's not fair to the dog. :(

[AGlobalThreat]

2. Remove windshield fluid reservoir

Will there be any error codes or lights from doing this? Any negative side effects?

[mazilla]

don't forget to remove the headliner, and depending on your local codes you might only need one side mirror...I'm just sayin. ;)

[AGlobalThreat]

Haha thats my other car no joke. :)